Antioxidative effects of docosahexaenoic acid in the cerebrum versus cerebellum and brainstem of aged hypercholesterolemic rats

Female Wistar rats (100 weeks old) were divided into two groups; one group was fed a high-cholesterol diet (HC) and the other a high-cholesterol diet plus docosahexaenoic acid (HC-fed DHA rats). Fatty acid concentrations in b rain tissues were analyzed by gas chromatography. In the HC-fed DHA rats, b rain catalase (CAT), GSH, and glutathione peroxidase (GPx) increased in the cerebrum but not in the brainstem or cerebellum. The rate of increase was 23.0% for CAT, 24.5% for GSH, and 26.3% for GPx compared with that in the H C animals (p < 0.05). In the cerebrum of the HC-fed DHA rats, CAT and GPx i ncreased, with an increase in the ratio of DHA to arachidonic acid. The cer ebrum, unlike the other areas of the brain, seems to be more sensitive to D HA in stimulating CAT and GPx. We suggest that DHA plays an important role in inducing an antioxidative defense against active oxygen by enhancing the cerebral activities of CAT, GPx, and GSH.